The present disclosure relates generally to the field of hydrocarbon synthesis. More particularly, but not exclusively, it relates to processes for the liquefaction of carbonaceous feedstocks, including lignite and coal.
Coal liquefaction is the process of producing synthetic liquid fuels from coal and other carbonaceous feedstocks. Such processes have been generally known for nearly 90 years. See, for example, Coliquefaction Studies of Waste Polymers and Lignite Influenced by Acidic and Oil-Soluble Catalysts (Gimouhopoulos et al., 2000); Influence of Heterogeneous Catalysts on the Coprocessing of Bergueda Lignite with a Vacuum Residue (Bengoa et al., 1997); Coprocessing of Bergueda Lignite with Vacuum Residue under Increasing Hydrogen Pressure. Comparison with Hydrotreating (Bengoa et al., 1995); Influence of Fe and FeMo High Loading Supported Catalysts on the Coprocessing of two Spanish Lignites with a Vacuum Residue (Font et al., 1994); Study of Iron-Based Complex Catalysts For Coal Liquefaction (Sun et al, 1989); Evaluation of the Hydroliquefaction Potential of Chinese Coals: Three Case Studies (Gao et al., 1989); Catalytic Conversions of Kansk-Achinsk Lignite to Synthetic Fuels and Chemicals (Kuznetsov et al., 1988); Hydrogenation of Lignite by Synthesis Gas (Kuznetsov et al., 1988); Function of Metal Oxide and Complex Oxide Catalysts for Hydrocracking of Coal (Tanabe et al., 1986); Catalytic Functions of Iron Catalysts for Hydrocracking of Carbon-Carbon and Carbon-Oxygen Bonds (Hattori et al., 1985); U.S. Pat. No. 5,509,945; U.S. Pat. No. 5,200,063; U.S. Pat. No. 5,071,540; U.S. Pat. No. 5,026,475; U.S. Pat. No. 4,853,111; U.S. Pat. No. 4,842,719; U.S. Pat. No. 4,839,030; U.S. Pat. No. 4,816,141; U.S. Pat. No. 4,728,418; U.S. Pat. No. 4,459,138; U.S. Pat. No. 4,385,042; U.S. Pat. No. 4,383,094; U.S. Pat. No. 4,356,079; U.S. Pat. No. 4,334,977; U.S. Pat. No. 4,332,666; U.S. Pat. No. 4,325,801; U.S. Pat. No. 4,311,578; U.S. Pat. No. 4,303,494; U.S. Pat. No. 4,300,996; US 20080011643; US 20060032788; and US 20020179493. Processes using hydrogenated coal tar distallate as the solvent have been demonstrated. See, for example, Neavel et al. (1981) and Mitchell et al. (1979).